A device for detecting an acceleration in one direction and a speed of rotation along one direction, including a support and two structures mechanically coupled to each other in opposite phase and suspended relative to the support, each of the structures including: an excitation mass; an excitation mechanism configured to move the excitation mass in a given direction; an inertial mass suspended to the excitation mass; a detector connected to the inertial mass to be displaced by same, and the detector connected to the support; a mechanism for detecting displacement of the inertial mass; and a controller controlling the excitation mechanism and processing signals delivered by the detecting mechanism.